He said he was "like a zombie" and felt as though he was "hypnotised" as he prowled silently around the car park at Sainsbury's in Hampton, west London, armed with a Leatherman knife.

Orhon, of Deacons Walk, Hampton, remained emotionless as he was given two 20-year sentences for two counts of attempted murder and two nine-year sentences for two counts of wounding with intent to cause grievous bodily harm. All sentences are to be served concurrently.

A jury at Kingston Crown Court took four hours and 55 minutes to find him guilty of all charges.

Judge Paul Dodgson told Orhon: "This was a planned attempt to kill albeit while the balance of your mind was disturbed. You took that knife intending to use it, intending to kill people."

The judge said he clearly has "an unusual personality", adding: "You are on your own and as a loner it may be you are someone who tends to brood on matters."

Two of his victims broke down in tears as the verdicts were read out.

Orhon had told the court he remembered assaulting one person and following two men.

These turned out to be schoolboys from Hampton Grammar, who warned other innocent passers-by that Orhon was armed and dangerous, distracted him and called 999.

Orhon said he had "no memory" of going to the car park or of the stabbings.

This is in contrast to footage from his police interviews, shown in court, where he said he had "rushed" at someone in the car park and he remembered "stabbing someone in the back".

Consultant forensic psychiatrist Dr Philip Joseph said Orhon, who had no previous contact with the medical services, is suffering from paranoid psychosis, which may put a person out of touch with reality.